Android 动态添加Fragment

public class MainActivity extends AppCompatActivity {    @SuppressWarnings("deprecation")    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //1 获取手机的分辨率        WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);        int width = wm.getDefaultDisplay().getWidth();        int heigth = wm.getDefaultDisplay().getHeight();        //2 判断横竖屏        //3 获取Fragment的管理者 通过上下文直接获取        FragmentManager fragmentManager = getFragmentManager();        FragmentTransaction beginTransaction = fragmentManager.beginTransaction(); // 开启事务        if (heigth > width) {            // 说明是竖屏 加载第一个Fragment android.R.id.content代表当前手机的窗体            beginTransaction.replace(android.R.id.content, new Fragment1()); // 注意这里定义的Fragment需要导入app.fragment包，而不是v4包。         } else {            // 说明是横屏 加载第二个Fragment            beginTransaction.replace(android.R.id.content, new Fragment2());        }        //4 最后一步 记得commit        beginTransaction.commit();    }}